Electric relays



May 23, 1961 B. BVEDE ELECTRIC RELAYS Filed May 8, 1959 l .l il wf :M/03 ya? Patented May 23, 1961 ELECTRIC RELAYS Bela Bede, London,England, assignor to New Electronic Products Limited, a company of GreatBritain Filed May 8, 1959, Ser. No. 812,060

AClaims priority, application Great Britain Jan. 19, 1959 9 Claims. (Cl.ZOU- 1103) This invention relates to electric relays.

The main object of the invention is to provide a relay which is sobalanced that no acceleration or spin imposed upon it will cause it tooperate.

A second object is the provision of a relay having a number ofindependent contacts which are separately adjustable.

With the above-stated main object in mind, the invention provides arelay comprising a base, a pair of similar armatures mounted upon thebase for pivotal movement with respect thereto about parallel axes, acore and coil also mounted on the base, the core presenting poles to thearmature such that energization of the coil causes them to pivot inopposite angular directions against the action of a bias, meansinterconnecting the armatures such that the movement of one is alwaysequal and opposite to that of the other, and at least one contactactuated on movement of the armatures.

The armature interconnecting means preferably comprises first and secondrigid arms extending one from one armature and one from the other in aplane perpendicular to that in which the armature pivot axes lie, onearm having a tubular end portion and the other mounting near its end aball which fits snugly within the interior of said tubular end portionand lies substantially equidistantly from both armature pivot axes.

A furtherl important feature of the relay lies in the means foractuating the contact or contacts, which preferably comprise a pin(conveniently an adjustable screw) extending from one (or from each)armature and a micro switch located in the path of the movement of theend of the (or each) pin which takes place upon movement of thearmatures. There is no theoretical limit to the number of contacts whichthe relay can actuate; each pin may be adjusted separately without theadjustment having any effect on the other contacts; moreover, by reasonof the micro switch action, the contact operation will be reasonablyfast. The contact actuating means just described may be used in relaysother than such as specified in the fourth paragraph hereof.

Yet another important feature of the relay according to the inventionconcerns the bias applied to the armatures: preferably this bias isprovided by a permanent magnet, which conveniently can be made to actupon a part of each armature on the opposite side of its axis to suchpart es is aiiected by the corresponding pole on the core of the coil.This bias avoids the use of springs, which under certain conditions ofvibration may resonate and render the relay unreliable.

One form of relay embodying the invention and a modication thereof,willL now be described by way of example with reference to theaccompanying diagrammatic drawings, in which:

Figure l is a diagrammatic perspective view of the relay;

Figure 2 is a perspective diagram illustrative of the armatureinterconnecting means, and

Figure 3 is a perspective view of the modified relay.

Referring to Figures l and 2 of the drawings, the relay comprises arectangular plate-like base 1 of soft magnetic material. At each end ofthe base a pair of lugs 2 is secured by screws to one side of the baseand extends beyond the end of the base in the general plane thereof.Generally rectangular plate-like armatures 3, 4 are mounted at the endsof the base, one between each pair of lugs 2, by means of pins 5 carriedby the lugs and defining pivot axes for the armatures which are parallelto each other and lie in the general plane of the base: each pivot axispasses through the centre of gravity of the corresponding armature. Awire spring 6 is mounted on each pair of lugs, so as to bias the upperend of the corresponding armature towards the base.

A plate-like core 8 of soft magnetic material having the same generaldimensions as the base 1 is mounted below and parallel to the base onnon-magnetic posts 9. The core 8 carries a coil 10 and provides poles atits ends 11, 12. Energization of the coil 10 causes the armatures 3, 4to move in opposite angular directions to bring their lower ends intocontact with the poles 11, 12, the magnetic circuit running through thebase 1, core 8 and the lower parts of the armatures 3, 4.

Each armature 3, 4 has a lateral extension, 15, 16 carrying a rigid arm17, 18 perpendicular to the armature. The arm 17 is tubular, at least atits free end portion, and is slit at 19. The arm 18 has a strip-likeextension 20 with a hole 21 near its free end which locates a ball 22(preferably of sapphire for lightness and strength) fitting snuglywithin the arm 17 and lying equidistantly from the armatures.

The arms 17, 18 interconnect the armatures 3, 4 so that movement of oneis always equal and opposite to that of the other. On movement of thearmatures, the ball 22 moves in the arm 17 and the extension 2) movesfreely in the slit 19.

Each armature 3, 4 has near its upper edge a tapped hole perpendicularto its general plane which adjustably receives a screw 25, 26. The innerends of the screws 25, 26 co-operate respectively with micro-switches27, Z3 mounted on the base 1, and are in continuous Contact therewith.The micro switches 27, 28 are of conventional construction and comprisea light springmetal contact arm 29 mounted at one end 30 and with itsother end making contact with one or other of two contact posts 31, 32.In the un-energized condition of the coil 10 the micro switch arms 29contact the posts 31: when upon energization of coil 10 the screws 25,26 move apart, the arms 29 contact the posts 32 due to bias in the arms.This latter bias is, of course, insutiicient to overcome that providedby the wire springs 6.

It will be appreciated that the relay is balanced against allaccelerations and spin, that the contacts are independently adjustable,and that within reason any number may be provided as conditions of usemay dictate.

In the relay of Figures l and 2 the ybias on the armatures is providedby wire springs. Now under certain conditions of vibration these springsmay resonate and fail to provide the required bias, so rendering therelay unreliable. The modified form of relay shown in Figure 3 isdesigned to avoid this drawback: apart from the bias on the armatures itis generally similar to that of Figures l and 2, corresponding partsbeing designated by similar reference numerals distinguished by a prime.However compared with the relay of Figures l and 2 that of Figure 3 isinverted and differs also in being mounted on a base plate of insulatingmaterial, the base 1' being secured thereto by stout brass posts (notshown). Other minor differences concern the lugs 5 which are hereintegral with the base 1', and the micro switch 27 which is here mountedon the base plate 100 on the outside of the armature 3 which actuatesit.

A pair of similar pole bars 101, 102 of soft magnetic material aremounted on the base 1 in spaced relation thereto and on the sideopposite the coil by means ol' brass posts (not shown). Each pole-bar101, I102 presents'onc edge towards one of the armatures 3', 4 therelative positions of armature and `pole bar being the same at eacharmature. A permanent magnet 103 is mounted between the pole bars 101,`102 by means of a brass clamping plate 104: each end of the magnetrests on one of the pole bars and the clamping plate, which extendsbeyond the magnet, is held to the pole bars by screws 105.

The magnetic circuit due to the coil 10 passes through the core Stherefor, the upperhalf of each of the armatures 3', 4 and the base 1.The magnetic circuit due to the permanent magnet 103 passes through thepole bars 1011, 102 the lower half of each of the armatures 3 and d andthe base 1'. The magnet l03'sets up a bias on each armature 3', 4tending to move it in a direction opposite to that in which it is movedon energization of the coil 10', the bias onthe two armatures lbeingequal and opposite due to the symmetrical arrangement of armatures andpole bars 101, 102. The bias due to the magnet 103 is suicient to holdthe upper ends of the armatures 3', 4 away from the core 8 when the coil10 is unenergized.

Energization of the coil by a current of. the magnitude to which therelay is desired to respond moves the upper ends of the armatures 3', 4towards the core 8 against the bias due to the magnet 103.

It will be understood that the permanent magnet described dispenses withthe need for springs, and that there is nothing in the relay which canresonate no matter how it is vibrated.

I claim:

1. An electric relay comprising a base, a pair of similar armaturesmounted upon the base for pivotal movement with respect thereto aboutparallel axes, a core and a coil also mounted on the base, the corepresenting poles to the armature such that energization of the coilcauses them to pivot in opposite angular directions against the actionof a bias, means interconnecting the armatures such that the movement ofone is always equal and opposite to that of the other, and at least onecontact actuated on movement of the armatures, said armatureinterconnecting means comprising rst and second rigid arms extending onefrom one armatureand one from the other in a plane perpendicular to thatin which the armature pivot axes lie, one arm having a tubular endportion and the other mounting near its end i a rounded portion whichiits snugly within the interior of said tubular end portion and liessubstantially equidistantly from both armature pivot axes.

2. A relay as claimed in claim l, wherein the rounded portion is asapphire.

3. A relay as claimed in claim l, further comprising at least one microswitch providing said contact, at least one pin extending from one ofsaid armatures, the nurnber of said pins beingV equal to the number ofsaid micro switches and each pin being located to operate onemicroswitch on movement of the armatures.

4. A relay as claimed in claim l, wherein said bias on the armatures isprovided by a permanent magnet- 5. An electric relay comprising a plateof soft magnetic material forming a base and presenting a pair ofparallel edges, a pair of similar plates of soft magnetic materialforming armatures, means symmetrically and pivotally mounting saidarmatures on parallel pivot axes and closely adjacent said ledges of theVbase whereby a plane perpendicular to said edges is `also perpendicularto thesurface of said armatures, means interconnecting the armatures formovement together symmetrically and in opposite angular directions, aplate-like core of soft magnetic material mounted on said base andparallel thereto by non-ferromagnetic means, said core presentingopposite edge surfaces adapted to contact the surfaces of the armatureswhen the latter are pivoted towards the core, a coil on the core,energization of said coil, setting up a magnetic circuit through thecore, the armatures and the base whereby to pivot the armatures towardssaid core against a bias, and at least one contact actuated on movementof said armatures.

6. A.l relay as claimed in claim 5, wherein said pivot axes of thearmatures contain their centres of gravity whereby each armature has arst portion to one side of its axis which portion forms part of saidmagnetic circuit and a second portion to the other side of its axiswhich portion does not form a part of said magnetic circuit, andsaid-bias is provided by a permanent magnet mounted on thefbase to theside thereof opposite said core by non-ferromagnetic means, said magnetforming a second magnetic circuit with the second portion of eacharmature and the base.

7. An electric relay comprising a base, a pair of members mounted uponthe base for pivotal movement with respect thereto about parallel axes,means interconnecting said members for symmetrical movement thereof inopposite angular directions, means including a coil rigid with the baseto pivot said members against the action of a bias on energization'ofthe coil, and a Contact arranged for actuation on movement of saidmembers, said interconnecting means comprising iirst and second rigidarms extending one from one said member and one from the other member ina plane perpendicular to that in which the pivot axes of said memberslie, one arm having a tubular end portion and the other mounting nearits end a ball which ts snugly within the interior of said tubular endportion and lies substantially equidistantly from both pivot axes. i

8. An electric relay comprising a base, a pair of similar armaturesmounted upon the base for pivotal movement with respect thereto aboutparallel axes, a core and coil also mounted, on the base, the corepresenting poles to the armature such that energization of the coilcauses them to pivot in opposite angular directions against the actionof a bias, means interconnecting the armatures such that the movement ofone if always equal and opposite to that of the other, and at least onecontact actuated on ,movement of the armatures, wherein a permanentmagnet provides said bias on the armatures and wherein each armatureextends to either side of its pivot axis, the part of each armature toone side of its pivot forming on energization of the coil, a portion ofa first magnetic circuit including the core and the base, and the partof each armature to the other side of its pivot axis forming a portionof a second magnetic circuit including the permanent magnet and thecase.

9. A relay as claimed in claim 8, further comprising at least one microswitch providing said contact, at least one pin extending from one ofsaid armatures, the number of said pins being equal to the number ofsaid micro switches and each pin being located to operate one microswitch on movement of the armatures.

References Cited in the file of this patent UNITED STATES PATENTS1,700,890 Hodgkins et al. Feb. 5, 1929 2,353,377 Vaughn July l1, 19442,632,820 Gauvreau Mar. 24, 1953

